1. Field of the Invention
The present invention relates to bottle caps for medicine bottles, and more particularly, to a bottle cap having a desiccant retained therein for preventing contamination of the medicine by moisture.
2. Description of the Related Art
Many drugs are typically bottled in an atmosphere of very low humidity to avoid absorption of moisture within the container. However, each time the bottle is opened by the consumer for removal of a portion of the contents, atmospheric air is admitted to the container. This results in an increase in humidity within the bottle and eventual deterioration of the contents. In order to maintain a moisture-free atmosphere within the bottle after it has been opened, packagers frequently place therein a pill of desiccant material or a moisture-permeable capsule containing a desiccant. However, the danger always exists that the consumer may inadvertently remove or even take the desiccant pill or capsule. Since these desiccants often contain a cobalt salt to indicate exposure to humid atmospheres, ingestion of such materials can result in discomfort or serious illness.
Consequently, a bottle cap having a desiccant material attached thereto in a manner which prevents its becoming readily detached is desirable. While prior attempts have been made to provide a bottle cap of this type, most cap structures of this type are configured to include a desiccant chamber consisting of a separate unit mechanically integrated with the complete cap. Such structures have not been accepted by the drug and chemical packaging houses because they involve the use of caps of extra size or shape. Their use would entail considerable expense and trouble in adapting present machinery to accommodate them and in making and handling cartons in which the bottles of packaged material are packed. The inconvenience of such change has been so great that the present cap structures of this type have not been acceptable.
U.S. Pat. No. 2,317,882, issued Apr. 27, 1943 to C. F. Boesel, discloses closure caps for receptacles containing dry medicinal materials. The cap includes a separate housing made of plastic or metal for receiving an absorbent or dehydrating means to protect the medicinal materials from moisture.
U.S. Pat. No. 3,035,730, issued May 22, 1962 to P. G. Walker, discloses a bottle cap having a desiccant chamber formed in a central portion of the liner and a desiccant material retained therein by means of a closure member.
U.S. Pat. No. 3,254,784, issued Jun. 7, 1966 to F. Lancesseur, discloses a dehydrating stopper having a washer disposed between the stopper bottom and a pad of dehydrating product, the washer having printed thereon the mark or trade name of the product contained in the bottle or other container which is to be closed by means of the stopper.
U.S. Pat. No. 4,350,508, issued Sep. 21, 1982 to Santoro et al., discloses a desiccant cap. The desiccant cap is a transparent enclosure having an internal cavity divided into two portions, the first of which is designed to accept and seal a container. The second is designed to accept and hold a mixture of a desiccant and a humidity sensitive color indicator. The first and second portions of the cavity are separated by a barrier wall which contains a filter in the central area of the wall. The filter is formed from a wicking polymer.
U.S. Pat. No. 4,545,492, issued Oct. 8, 1985 to R. A. Firestone, discloses a device for maintaining dry conditions in vessels. The device is a cap or stopper having a hollow section to contain a drying agent, a nonporous top member having at least one pinhole therein and a porous bottom member.
Other patents related to desiccant holding devices for medicine bottles include U.S. Pat. No. 6,274,209, issued Aug. 14, 2001 to Pagidas et al. (semipermeable venting closure); U.S. Pat. No. 4,394,144, issued Jul. 19, 1983 to Y. Aoki (dehumidifying container); U.S. Pat. No. 4,287,995, issued Sep. 8, 1981 to T. Moriya (container sealing member with oxygen absorbent); U.S. Pat. No. 4,279,350, issued Jul. 21, 1981 to R. V. King (closure with oxygen scavenging system); U.S. Pat. No. 4,146,277, issued Mar. 27, 1979 to D. S. Santoro (desiccant cap); United Kingdom Patent No. 2,098,501, published Nov. 24, 1982 (dehumidifying container); European Patent No. 222,102, published May 20, 1987 (closure with a desiccant); and European Patent No. 978,306, published Feb. 9, 2000.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a desiccant bottle cap solving the aforementioned problems is desired.